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| United States Patent |
5,725,791
|
|
Bivens
, et al.
|
March 10, 1998
|
Azeotropic and azeotrope-like compositions of 1,1,2,2-tetrafluoroethane
Abstract
The azeotropic compositions of 1,1,2,2-tetrafluoroethane and
1,1-difluoroethane and the azeotropic and azeotropic-like composition of
1,1,2,2-tetrafluoroethane and one of, 1-chloro-1,1-difluoroethane,
perfluorocyclobutane, n-butane, isobutane and
1,1,1,2,3,3,3-heptafluoropropane, and their use as refrigerants, aerosol
propellants and blowing agents for polymer foams, are disclosed. The
azeotropic and azeotrope-like compositions of 1,1,1,2-tetrafluoroethane
and one of perfluorocyclobutane and 1,1,1,2,3,3,3-heptafluoropropane are
also useful as fire extinguishants.
| Inventors:
|
Bivens; Donald Bernard (Kennett Square, PA);
Lunger; Brooks Shawn (Newark, DE);
Yokozeki; Akimichi (Greenville, DE)
|
| Assignee:
|
E. I. du pont de Nemours and Company (Wilmington, DE)
|
| Appl. No.:
|
104384 |
| Filed:
|
August 9, 1993 |
| Current U.S. Class: |
252/67; 62/114; 62/324.1; 252/364; 510/177; 510/408 |
| Intern'l Class: |
C09K 005/04; C09K 003/30; C11D 007/30 |
| Field of Search: |
252/67,162,172,305,364,DIG. 9
62/114,324.1
264/53,DIG. 5
521/98,131
424/45
510/177,408
|
References Cited
U.S. Patent Documents
| 3732150 | May., 1973 | Bailey | 203/44.
|
| 3819493 | Jun., 1974 | Fozzard | 203/70.
|
| 5348730 | Sep., 1994 | Greenleaf et al. | 424/45.
|
| Foreign Patent Documents |
| 430170 | Jun., 1991 | EP.
| |
| 451692 | Oct., 1991 | EP.
| |
| 483573 | May., 1992 | EP.
| |
| 277132 | Feb., 1978 | DE.
| |
| 4003272 | Aug., 1991 | DE.
| |
| 63-308084 | Dec., 1988 | JP.
| |
| 63-308085 | Dec., 1988 | JP.
| |
| 1108291 | Apr., 1989 | JP.
| |
| 3168287 | Jul., 1991 | JP.
| |
| 4-36377 | Feb., 1992 | JP.
| |
| 91/09089 | Jun., 1991 | WO.
| |
| 91/16390 | Oct., 1991 | WO | 252/172.
|
Other References
Maezawa et al., ASME/JSME Thermal Engineering Proceedings, vol. 3, pp.
443-449, Mar. 1991.
Tamatsu et al., J. Chem. Eng. Data, vol. 37, pp. 512-515, 1992, no month
available.
|
Primary Examiner: McGinty; Douglas J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 07/837,416 filed
Feb. 20, 1992, now abandoned, which is a division of 08/676,637, filed
Mar. 28, 1991, now U.S. Pat. No. 5,182,040.
Claims
We claim:
1. An azeotropic composition consisting essentially of about 80-99 weight
percent 1,1,2,2-tetrafluoroethane and about 1-20 weight percent
1,1-difluoroethane, wherein the dew point and the bubble point are both
about -19.6.degree. C. at 14.7 psia.
2. An azeotropic composition consisting essentially of about 92 weight
percent 1,1,2,2-tetrafluoroethane and about 8 weight percent
1,1-difluoroethane wherein the dew point and the bubble point are both
about -19.6.degree. C. at 14.7 psia, said composition having a boiling
temperature of about 10 degrees C. when the pressure is adjusted to about
46 psia.
3. A process of producing refrigeration which comprises condensing the
azeotropic composition of claim 1 and thereafter evaporating said
composition in the vicinity of a body to be cooled.
4. An aerosol propellant composition consisting essentially of the
azeotropic composition of claim 1.
5. The aerosol propellant composition of claim 4 consisting essentially of
about 97.4 weight percent 1,1,2,2-tetrafluoroethane and about 2.6 weight
percent difluoroethane.
Description
FIELD OF THE INVENTION
This invention relates to azeotropic and azeotrope-like mixtures of
1,1,2,2-tetrafluoroethane (HFC-134) and one of 1,1-difluoroethane
(HFC-152a), 1-chloro-1,1-difluoroethane (HCFC-142b),
1,1,1,2,3,3,3,-heptafluoropropane (HFC-227ea), perfluorocyclobutane
(FC-C318), n-butane or isobutane and their use as refrigerants, aerosol
propellants and blowing agents for polymer foams. The azeotropic and
azeotrope-like compositions of 1,1,1,2-tetrafluoroethane and one of
perfluorocyclobutane and 1,1,1,2,3,3,3-heptafluoropropane are also useful
as fire extinguishants. As used herein, extinguishant means the active
ingredient used to extinguish fires.
BACKGROUND OF THE INVENTION
The mixtures of the present invention are useful as refrigerants, heat
transfer media, gaseous dielectrics, foam expansion agents, aerosol
propellants and power cycle working fluids. These mixtures are potentially
environmentally safe substitutes for commercial refrigerants such as
dichlorodifluoromethane (CFC-12).
Closed-cell polyurethane foams are widely used for insulation purposes in
building construction and in the manufacture of energy efficient
electrical appliances. In the construction industry, polyurethane
(polyisocyanurate) board stock is used in roofing and siding for its
insulation and load-carrying capabilities. Poured and sprayed polyurethane
foams are also used in construction. Sprayed polyurethane foams are widely
used for insulating large structures such as storage tanks, etc.
Pour-in-place polyurethane foams are used, for example, in appliances such
as refrigerators and freezers, plus they are used in making refrigerated
trucks and railcars.
All of these various types of polyurethane foams require expansion agents
(blowing agents) for their manufacture. Insulating foams depend on the use
of halocarbon blowing agents, not only to foam the polymer, but primarily
for their low vapor thermal conductivity, a very important characteristic
for insulation value. Historically, polyurethane foams are made with
trichlorofluoromethane (CFC-11) as the primary blowing agent.
A second important type of insulating foam is phenolic foam. These foams,
which have very attractive flammability characteristics, are generally
made with CFC-11 and CFC-113 blowing agents.
A third type of insulating foam is thermoplastic foam, primarily
polystyrene foam. Polyolefin foams (polyethylene and polypropylene) are
widely used in packaging. These thermoplastic foams are generally made
with CFC-12.
Many refrigeration applications, e.g. refrigerators, auto and window air
conditioners, etc., presently use CFC-12 as the refrigerant. HFC-134 is a
fluorocarbon compound identified as a potential replacement for CFC-12,
having properties near those of CFC-12, and being nonflammable with a zero
ozone depletion potential. HFC-134 has a thermodynamic refrigeration
coefficient of performance somewhat better than that of CFC-12, which may
result in energy saving refrigeration applications when HFC-134 is
substituted for CFC-12.
Many products designed for household, personal or industrial use are
available as aerosol products. Typical examples of such products and ones
in which the propellant system of the present invention can be used
include personal products such as hair sprays, deodorants and colognes;
household products such as waxes, polishes, pan sprays, room fresheners
and household insecticides; industrial products such as cleaners,
lubricants, and mold release agents; and automotive products such as
cleaners and polishes. All such products utilize the pressure of a
propellant gas or a mixture of propellant gases (i.e., a propellant gas
system) to expel the active ingredients from the container. For this
purpose, most aerosols employ liquified gases which vaporize and provide
the pressure to propel the active ingredients when the valve on the
aerosol container is pressed open.
An important physical property associated with the dispensing of aerosol
products is the vapor pressure of the propellant. Vapor pressure from the
viewpoint of this invention is the pressure exerted when a liquified
propellant gas is in equilibrium with its vapor in a closed container,
such as an aerosol can. Vapor pressure can be measured by connecting a
pressure gauge to the valve on an aerosol can or gas cylinder containing
the vapor/liquid mixture. A standard of measurement of vapor pressure in
the U.S. aerosol industry is pounds per square inch gauge (psig) with the
gas/liquid mixture at constant temperature, most commonly at 70.degree. F.
(21.degree. C.). The vapor pressures of liquified gases most widely
employed as aerosol propellants will vary over the range of about 20 to 90
psig (239 to 722 kPa) at 70.degree. F. (21.degree. C.). The propellant
systems of the present invention have vapor pressures in this latter
range.
In the early 1970s, concern began to be expressed that the stratospheric
ozone layer (which provides protection against penetration of the earth's
atmosphere by ultraviolet radiation) was being depleted by chlorine atoms
introduced to the atmosphere from the release of fully halogenated
chlorofluorocarbons. These chlorofluorocarbons are used as propellants in
aerosols, as blowing agents for foams, as refrigerants and as
cleaning/drying solvent systems. Because of the great chemical stability
of fully halogenated chlorofluorocarbons, according to the ozone depletion
theory, these compounds do not decompose in the earth's atmosphere but
reach the stratosphere where they slowly degrade, liberating chlorine
atoms which in turn react with the ozone.
Concern reached such a level that in 1978 the U.S. Environmental Protection
Agency (EPA) placed a ban on nonessential uses of fully halogenated
chlorofluorocarbons as aerosol propellants. This ban resulted in a
dramatic shift in the U.S. away from chlorofluorocarbon propellants
(except for exempted uses) to primarily hydrocarbon propellants. However,
since the rest of the world did not join the U.S. in this aerosol ban, the
net result has been to shift the uses of chlorofluorocarbons in aerosols
out of the U.S., but not to permanently reduce the world-wide total
chlorofluorocarbon production, as sought. In fact, in the last few years
the total amount of chlorofluorocarbons manufactured worldwide has
exceeded the level produced in 1978 (before the U.S. ban).
During the period of 1978-1987, much research was conducted to study the
ozone depletion theory. Because of the complexity of atmospheric
chemistry, many questions relating to this theory remained unanswered.
However, assuming the theory to be valid, the health risks which would
result from depletion of the ozone layer are significant. This, coupled
with the fact that worldwide production of chlorofluorocarbons has
increased, has resulted in international efforts to reduce
chlorofluorocarbon use. Particularly, in September, 1987, the United
Nations through its Environment Programme (UNEP) issued a tentative
proposal calling for a 50 percent reduction in worldwide production of
fully halogenated chlorofluorocarbons by the year 1998. This proposal was
ratified Jan. 1, 1989 and became effective on Jul. 1, 1989.
Because of this proposed reduction in availability of fully halogenal
chlorofluorocarbons such as CFC-11, CFC-12 and CFC-113, alternative, more
environmentally acceptable, products are urgently needed.
As early as the 1970s with the initial emergence of the ozone depletion
theory, it was known that the introduction of hydrogen into previously
fully halogenated chlorofluorocarbons markedly reduced the chemical
stability of these compounds. Hence, these now destabilized compounds
would be expected to degrade in the atmosphere and not reach the
stratosphere and the ozone layer. The accompanying Table I lists the ozone
depletion potential for a variety of fully and partially halogenated
halocarbons. Halocarbon Global Warming Potential data (potential for
reflecting infrared radiation (heat) back to earth and thereby raising the
earth's surface temperature) are also shown.
TABLE I
______________________________________
OZONE DEPLETION AND GREENHOUSE POTENTIALS
Halocarbon
Ozone Depletion
Global Warming
Blowing Agent Potential Potential
______________________________________
CFC-11 (CFCl.sub.3)
1.0 1.0
CFC-12 (CF.sub.2 Cl.sub.2)
1.0 3.1
HCFC-22 (CHF.sub.2 Cl)
0.05 0.34
HCFC-123 (CF.sub.3 CHCl.sub.2)
0.02 0.02
HCFC-124 (CF.sub.3 CHFCl)
0.02 0.1
HFC-134a (CF.sub.3 CH.sub.2 F)
0. 0.28
HFC-134 (CHF.sub.2 CHF.sub.2)
0. 0.3
(est.)
HCFC-141b (CFCl.sub.2 CH.sub.3)
0.15 0.15
HCFC-142b (CF.sub.2 ClCH.sub.3)
0.06 0.36
HFC-152a (CHF.sub.2 CH.sub.3)
0. 0.03
CFC-113 (CF.sub.2 Cl--CFCl.sub.2)
0.8 1.4
FC-C318 (CF.sub.2 --CF.sub.2) (CF.sub.2 --CF.sub.2)
0. Not available
HFC-227ea (CF.sub.3 CHFCF.sub.3)
0 Not available
______________________________________
Halocarbons such as HFC-134, HFC-152a, HFC-227ea and FC-C318 have zero
ozone depletion potential. N-butane and isobutane, having no halogen
content, are also zero ozone depleters. HCFC-142b has an ozone depletion
potential of 0.06.
Although 1,1,2,2-tetrafluoroethane has utility as a refrigerant, aerosol
propellant or foam blowing agent, azeotropes offer the possibility of
producing more economical nonfractionating systems with improved
properties such as refrigeration performance, polymer and refrigerant oil
solubility.
Unfortunately, as recognized in the art, it is not possible to predict the
formation of azeotropes.
This fact obviously complicates the search for new azeotropes which have
application in the field. Nevertheless, there is a constant effort in the
art to discover new azeotropic compositions, which have desirable
characteristics.
SUMMARY OF THE INVENTION
In accordance with the present invention, azeotropic or azeotrope-like
mixtures have been discovered, which comprise effective amounts of
1,1,2,2-tetrafluoroethane (HFC-134) and one of 1,1-difluoroethane
(HFC-152a), 1-chloro-1,1-difluoroethane (HCFC-142b),
1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), perfluorocyclobutane
(FC-C318), n-butane or isobutane.
In accordance with the present invention, azeotropic or azeotrope-like
mixtures have been discovered, which consist essentially of effective
amounts of 1,1,2,2-tetrafluoroethane (HFC-134) and one of
1,1-difluoroethane (HFC-152a), 1-chloro-1,1-difluoroethane (HCFC-142b),
1,1,1,2,3,3,3-heptafluoropropane HFC-227ea, perfluorocyclobutane
(FC-C318), n-butane or isobutane, preferably the azeotropic mixture of
HFC-134 and 1 to 20 weight percent of HFC-152a.
The azeotropes of HFC-134 and one of HCFC-142b, n-butane, HFC-227ea,
isobutane and FC-C318 are minimum boiling azeotropes; thus, the vapor
pressure is higher and the boiling point lower for the azeotropes than for
the components. The azeotrope of HFC-134 and HFC-152a is a maximum boiling
azeotrope; thus, the vapor pressure is lower and the boiling point higher
for the azeotrope than for the components.
DETAILED DESCRIPTION OF THE INVENTION
The novel azeotropic or azeotrope-like compositions of the invention were
discovered during a phase study wherein the compositions were varied and
vapor pressures measured. By this procedure the following azeotropic
compositions reported in Table II were discovered:
TABLE II
______________________________________
Vapor
Pressure,
Components Composition*
Temp. .degree.C.
psia (kPa)
______________________________________
HFC-134/HFC-152a
92.0/8.0 10 46.5 (321)
HFC-134/HCFC-142b
95.9/4.1 -17 16.6 (114)
HFC-134/FC-C318
62.3/37.7 0 36.9 (254)
HFC-134/n-butane
83.1/16.9 10 56.9 (392)
HFC-134/isobutane
76.7/23.3 10 63.5 (438)
HFC-134/HFC-227ea
52.0/48.0 -10 23.5 (162)
______________________________________
*All compositions are .+-. 2 wt. percent.
Atmospheric Boiling Points of Components, .degree.C.
______________________________________
HFC-134 -19.5 n-butane -0.5
HFC-152a -25.0 Isobutane -11.7
HCFC-142b -9.8 HFC-227ea -18.0
FC-C318 -6.1
______________________________________
For the purpose of this discussion, azeotropic, azeotropic-like or constant
boiling is intended to mean also essentially azeotropic or essentially
constant boiling. In other words, included within the meaning of these
terms are not only the true azeotrope described above, but also other
compositions containing effective amount of the same components in
somewhat different proportions, which are true azeotropes at other
temperatures and pressures, as well as those equivalent compositions which
are part of the same azeotropic system and are azeotropic in their
properties. As is well recognized in this art, there is a range of
compositions which contain the same components as the azeotrope, which not
only will exhibit essentially equivalent properties for refrigeration and
other applications, but which will also exhibit essentially equivalent
properties to the true azeotropic composition in terms of constant boiling
characteristics or tendency not to segregate or fractionate on boiling.
It is possible to characterize, in effect, a constant boiling admixture,
which may appear under many guises, depending upon the conditions chosen,
by any of several criteria:
The composition can be defined as an azeotrope of A and B since the very
term "azeotrope" is at once both definitive and limitative, and requires
that effective amounts of A and B form this unique composition of matter,
which is a constant boiling admixture at a given pressure.
It is well known by those skilled in the art that at different pressures,
the composition of a given azeotrope will vary--at least to some
degree--and changes in pressure will also change--at least to some degree
the boiling temperature. Thus, an azeotrope of A and B represents a unique
type of relationship but with a variable composition which depends on
temperature and/or pressure. Therefore, compositional ranges, rather than
fixed compositions are often used to define azeotropes.
The composition can be defined as a particular weight percent relationship
or mole percent relationship of A and B while recognizing that such
specific values point out only one particular such relationship and that
in actuality, a series of such relationships, represented by A and B
actually exist for a given azeotrope, varied by the influence of pressure.
Azeotrope A and B can be characterized by defining the composition as an
azeotrope characterized by a boiling point at a given pressure, thus
giving identifying characteristics without unduly limiting the scope of
the invention by a specific numerical composition, which is limited by and
is only as accurate as the analytical equipment available.
It is recognized in the art that the difference between dew point
temperature and bubble point temperature is an indication of the constant
boiling or azeotrope-like behavior of mixtures. It has been unexpectedly
found that compositions some distance away from the azeotrope compositions
of this invention have differences in dew point/bubble point temperatures
of less than or equal to one degree Celsius. The small temperatures
differentials demonstrated by these compositions are less than values for
azeotrope-like ternary mixture of HCFC-22, HFC-152a, and HCFC-124
described in U.S. Pat. No. 4,810,403.
Therefore, included in this invention are the azeotrope-like compositions
having dew point/bubble point differences of less than or equal to one
degree Celsius reported in Table III. These data confirm the
azeotrope-like behavior of the compositions claimed in this invention. The
value for the ternary mixture of U.S. Pat. No. 4,810,403 is shown for
comparison.
TABLE III
______________________________________
Maximum Difference
In Dew Point/Bubble
Components Composition* Point Temp., .degree.C.
______________________________________
HCFC-22/HFC-152a/
36/24/40 5.3
HCFC-124
HFC-134/HFC-152a
1-20% HFC-152a
0.0
HFC-134/HCFC-142b
1-10% HFC-142b
0.0
HFC-134/HCFC-142b
1-40% HFC-142b
0.8
HFC-134/DME 1-40% DME 0.7
HFC-134/FC-C318
1-50% FC-C318
1.0
HFC-134/n-butane
1-20% n-butane
0.7
HFC-134/iso-butane
1-30% iso-butane
0.7
HFC-134/HFC-227ea
1-99% HFC-227ea
0.8
______________________________________
*weight percent; 14.7 psia pressure.
Most preferred compositions of this invention are the azeotropic
compositions having dew point/bubble point differences of less than or
equal to 0.1 degree Celsius as reported for HFC-134/HFC-152a in Table 3
and for such compositions containing about 80-99 weight percent HFC-134
and about 1-20 weight percent HFC-152a.
The azeotropic and azeotrope-like compositions of the invention are useful
as refrigerants, expansion agents and as aerosol propellants, among other
applications. The azeotropic and azeotrope-like compositions of
1,1,1,2-tetrafluoroethane and one of perfluorocyclobutane and
1,1,1,2,3,3,3-heptafluoropropane are also useful as fire extinguishants.
Mixtures of HFC-134, HFC-227ea, and FC-C318 are nonflammable. The
azeotropes of HFC-134 and HFC-152a or HCFC-142b are also nonflammable.
Additionally, mixtures of HFC-134 and n-butane, or isobutane can be
formulated such that they are nonflammable. Therefore, the azeotropic
compositions of HFC-134, n-butane, or isobutane are of significantly
reduced flammability compared with n-butane, or isobutane alone.
Another aspect of the invention is a refrigeration method which comprises
condensing a refrigerant composition of the invention and thereafter
evaporating it in the vicinity of a body to be cooled. Similarly, still
another aspect of the invention is a method for heating which comprises
condensing the invention refrigerant in the vicinity of a body to be
heated and thereafter evaporating the refrigerant.
In the heating and cooling applications, the nonflammable compositions are
particularly useful.
These azeotropic and azeotrope-like compositions are useful as propellants
for aerosol sprays, e.g., room fresheners. The azeotropes are particularly
attractive as they do not separate or fractionate when used in aerosol
packages equipped with vapor tap valves wherein the propellant is removed,
at least partially, vapor phase.
The binary refrigerant compositions of the invention are useful in
compression cycle applications including air conditioner and heat pump
systems for producing both cooling and heating. The new refrigerant
mixtures can be used in refrigeration applications as described in U.S.
Pat. No. 4,482,465 to Gray, which patent is incorporated herein by
reference.
The language "consisting essentially of 1,1,2,2-tetrafluoroethane" is not
intended to exclude the inclusion of minor amounts of other materials such
as lubricants and stabilizers which do not significantly alter the
azeotropic character of the azeotropic composition.
The compositions of the instant invention can be prepared by any convenient
method including mixing or combining, by other suitable methods, the
desired amounts of the components, using techniques well-known to the art.
Specific examples illustrating the invention are given below. Unless
otherwise stated therein, all percentages are by weight. It is to be
understood that these examples are merely illustrative and in no way to be
interpreted as limiting the scope of the invention.
EXAMPLE 1
A phase study was made on 1,1,2,2-tetrafluoroethane (HFC-134) and HFC-152a,
HCFC-142b, HFC-227ea, FC-C318, n-butane, and isobutane, respectively,
wherein the compositions were varied and the vapor pressures measured. The
following azeotropic compositions reported in Table IV were defined:
TABLE IV
______________________________________
Vapor Pressure,
Components Composition*
Temp. .degree.C.
psia (kPa)
______________________________________
HFC-134/HFC-152a
92.0/8.0 10 46.5 (321)
HFC-134/HCFC-142b
95.9/4.1 -17 16.6 (114)
HFC-134/FC-C318
62.3/37.7 0 36.9 (254)
HFC-134/n-butane
83.1/16.9 10 56.9 (392)
HFC-134/isobutane
76.7/23.3 10 63.5 (438)
HFC-134/HFC-227ea
52.0/48.0 -10 23.5 (162)
______________________________________
*All compositions are .+-. 2 wt. percent.
EXAMPLE 2
A determination was made of dew point and bubble point temperatures for the
mixtures of the invention, shown in Table V. All have temperature
differentials of less than or equal to one degree Celsius.
TABLE V
______________________________________
Temperature, .degree.C. at 14.7 psia
Composition, wt %
Dew Point Bubble Point
Difference
______________________________________
HFC-134/HFC-152a
99 1 -19.6 -19.6 0.0
92 8 -19.5 -19.5 0.0
90 10 -19.5 -19.5 0.0
80 20 -19.7 -19.7 0.0
HFC-134/HCFC-142b
99 1 -19.6 -19.6 0.0
95.9 4.1 -19.7 -19.7 0.0
90 10 -19.6 -19.6 0.0
70 30 -18.4 -18.9 0.5
60 40 -17.4 -18.2 0.8
HFC-134/FC-C318
99 1 -20.3 -19.9 0.4
95 5 -21.6 -20.6 1.0
90 10 -22.1 -21.2 0.9
70 30 -22.0 -22.2 0.2
62.3 37.7 -22.2 -22.2 0.0
60 40 -22.2 -22.2 0.0
50 50 -21.1 -22.1 1.0
HFC-134/n-butane
95 5 -24.6 -24.0 0.6
90 10 -24.4 -24.5 0.1
83.1 16.9 -24.6 -24.6 0.0
80 20 -23.9 -24.9 0.7
HFC-134/iso-butane
95 5 -27.4 -26.8 0.6
90 10 -27.8 -27.5 0.3
80 20 -27.8 -27.8 0.0
76.7 23.3 -27.7 -27.7 0.0
70 30 -27.1 -27.8 0.7
HFC-134/HFC-227ea
99 1 -19.7 -19.7 0.0
95 5 -19.8 -19.9 0.1
90 10 -20.0 -20.2 0.2
70 30 -20.8 -20.9 0.1
52 48 -21.1 -21.1 0.0
30 70 -20.3 -20.6 0.3
10 90 -18.0 -18.8 0.8
5 95 -17.2 -17.8 0.6
1 99 -16.5 -16.7 0.2
______________________________________
EXAMPLE 3
An evaluation of the refrigeration properties of the mixtures of the
invention versus dichlorodifluoromethane (CFC-12) and
1,1,2,2-tetrafluoroethane (HFC-134), respectively, are shown in following
Table VI. The data were generated on a one ton basis, that is to say, on
the removal of heat from a space at the rate of 12,000 Btu/hr (3516
watts). The data are based on the ideal refrigeration cycle.
TABLE VI
__________________________________________________________________________
COMPARISON OF REFRIGERATION PERFORMANCES
__________________________________________________________________________
Weight Percentages
62% HFC-134
CFC-12 HFC-134 38% C318
__________________________________________________________________________
Evaporator
Temp., .degree.F.
0 0 0
(.degree.C.)
(-17.7) (-17.7) (-17.7)
Press. psia 23.8 15.9 18.2
(kPa) (164.) (110.) (125.)
Condenser
Temp., .degree.F.
130 130 130
(.degree.C.)
(54.4) (54.4) (54.4)
Press. psia 195.7 170.5 181.8
(kPa) (1349.) (1175.) (1253.)
Superheat, .degree.F. 90 90 90
Subcool, .degree.F. 40 40 40
Coefficient of Performance
2.42 2.50 2.36
Displacement ft.sup.3 /min/ton
8.1 10.4 10.3
__________________________________________________________________________
Weight Percentages
90% HFC-134
75% HFC-134
90% HFC-134
52% HFC-134
83% HFC-134
77% HFC-134
10% HFC-152a
25% HCFC-142b
10% HCFC-142b
48% HFC-227ea
17% n-butane
23% isobutane
__________________________________________________________________________
Evaporator
Temp.,
.degree.F.
0 0 0 0 0 0
(.degree.C.)
(-17.7)
(-17.7) (17.7) (17.7) (17.7) (17.7)
Press.
psia 16.0 15.4 15.8 17.5 12.8 14.4
Condenser
Temp.,
.degree.F.
130 130 130 130 130 130
(.degree.C.)
(54.4) (54.4) (54.4) (54.4) (54.4) (54.4)
Press.
psia 169.7 161.4 167.3 178.6 141.1 148.5
(kPa) (1170.)
(1113.) (1153.) (1232) (974) (1025)
Superheat, .degree.F.
90 90 90 90 90 90
Subcool, .degree.F.
40 40 40 40 40 40
Coefficient of Performance
2.51 2.49 2.50 2.34 2.50 2.47
Displacement ft.sup.3 /min/ton
10.3 10.9 10.5 10.7 12.9 12.0
__________________________________________________________________________
Coefficient of Performance (COP) is a measure of refrigerant energy
efficiency.
Additives such as lubricants, corrosion inhibitors, stabilizers, dyes and
other appropriate materials may be added to the novel compositions of the
invention for a variety of purposes provided they do not have an adverse
influence on the composition, for their intended applications.
EXAMPLE 4
Aerosol room fresheners were prepared with the azeotropes of HFC-134 with
HFC-152a, HCFC-142b, DME, FC-C318, n-butane and isobutane. The
formulations and vapor pressures are reported in Table VII.
TABLE VII
______________________________________
AEROSOL ROOM FRESHENER FORMULATION
Wt. %
Ingredient 1 2 3 4 5
______________________________________
Perfume 2.0 2.0 2.0 2.0 2.0
Propellant* 98.0A 98.0B 98.0C 98.0D 98.0E
Vapor Pressure at 70.degree. F.,
55 54 74.5 69 76
psig
(21.degree. C., kPa)
(481) (474) (615) (578) (626)
______________________________________
*Propellants
A HFC134/HFC-152a (97.4/2.6)
B HFC134/HCFC-142b (96.8/3.2)
C HFC134/FC-C318 (62.1/37.9)
D HFC134/n-butane (82.5/17.5)
E HFC134/isobutane (74.0/26.0)
EXAMPLE 5
The solubilities of the HFC-134 azeotropes were determined in a
polyurethane polyol. The azeotropes of HFC-134 with HFC-152a, HCFC-142b,
n-butane and isobutane were readily soluble at 30.0 wt. % in the polyol,
as was HFC-134 itself. The solubility data are summarized in Table VIII.
TABLE VIII
______________________________________
SOLUBILITY OF HFC-134/DIMETHYL ETHER AZEOTROPE
IN POLYOL
Blowing Agent
Wt. % in Polyol*
Appearance
______________________________________
HFC-134 30.0 Soluble, single phase
HFC-134/HFC-152a
30.0 Soluble, single phase
(97.4/2.6)
HFC-134/HCFC-142b
30.0 Soluble, single phase
(96.8/3.2)
HFC-134/n-butane
30.0 Soluble, single phase
(82.5/17.5)
HFC-134/isobutane
30.0 Soluble, single phase
(74.0/26.0)
______________________________________
*Stepanpol PS2852 (Stepan Company), an aromatic polyester polyol.
EXAMPLE 6
The solubility of the HFC-134 azeotropes in polystyrene was determined by
combining a piece of polystyrene (about 2.5 cm long, 0.5 g cm wide and 0.5
cm thick) with about 50 g. azeotrope. Only the HFC-134/n-butane
(82.5/17.5) azeotrope had any appreciable solubility in polystyrene,
softening and deforming the piece of polystyrene. The data are summarized
in Table IX.
TABLE IX
______________________________________
SOLUBILITY OF HFC-134 AZEOTROPES IN POLYSTYRENE
Blowing Agent Appearance of Polystyrene
______________________________________
HFC-134 Essentially no effect
HFC-134/HFC-152a
Essentially no effect
(97.4/2.6)
HFC-134/HCFC-142b
Essentially no effect
(96.8/3.2)
HFC-134/FC-C318
Essentially no effect
(62.1/37.9)
HFC-134/n-butane
Polystyrene softened and deformed*
(82.5/17.5)
HFC-134/isobutane
Essentially no effect
(74.0/26.0)
______________________________________
*On removing the polystyrene from the azeotrope, expansion occurred from
solubilized HFC134.
EXAMPLE 7
A determination was made at dew point and bubble point temperatures for
mixtures of 1,1,2,2-tetrafluoroethane (HFC-134) and HFC-152a to determine
the azeotropic composition range, i.e., where the temperature differential
is less than 0.1 degree Celsius.
TABLE X
______________________________________
Composition. wt. %
Temperature .degree.C. at 14.7 psia.
HFC-134/HFC-152a
Bubble Pt. Dew Pt. Difference
______________________________________
30 70 -22.83 -22.3 0.53
40 60 -22.15 -21.63
0.52
50 50 -21.46 -21 0.46
54.7* 45.3 -21.13 -20.74
0.39
60 40 -20.78 -20.45
0.33
70 30 -20.16 -19.99
0.17
75 25 -19.9 -19.8 0.1
80 20 -19.7 -19.65
0.05
90 10 -19.5 -19.5 0
92 8 -19.5 -19.5 0
99 1 -19.6 -19.6 0
______________________________________
*Composition disclosed in Bailey U.S. Pat. No. 3,732,150.
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